This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The Warren Group has a long-term collaboration with Carola Leuschner of Louisiana State University to develop super paramagnetic iron oxide nanoparticles (SPIONs) to target cancer. A specific interest is to develop SPIONS that target metastatic lung cancer. This has been achieved and demonstrated by histologic techniques. A subsequent goal is to image the presence of such metasteses in vivo. This is a challenging goal because the primary contrast from SPIONS is to reduce T2*, but lung protons already have very short T2* rendering this effect unobservable. However, this problem is mitigated by using 3He MRI since 3He has a T2* >15 ms, therefore leaving ample dynamic range for observing T2* reduction in areas of targetted metasteses. Our specific aims in this pilot project are to perform a preliminary feasibility study to test whether 3He MRI can be used to detect lung cancer metastases in mouse models supplied by the Warren group. If we are successful in obtaining this preliminary in vivo data, it would be translated into a grant application.